如何从 UIImage 获取 URL

Question

How can I get an URL from UIImage? I've got an image from iPhone library and I resize it and I don't want to save the new image but I want to get it's URL.

Answer 1

You say you don't want to save it, but if you need a URL for a UIImage , you can easily save a temp copy to get the URL that you need.

For newer swift 5:

// Create a URL in the /tmp directory
guard let imageURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent("TempImage.png") else {
    return
}

let pngData = image.pngData();
do {
    try pngData?.write(to: imageURL);
} catch { }

Now you can use the URL to share the image to social media or whatever you need to do with it.

For previous Swift versions:

// Create a URL in the /tmp directory
guard let imageURL = NSURL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent("TempImage.png") else {
    return
}

// save image to URL
do {
    try UIImagePNGRepresentation(myImage)?.write(to: imageURL)
} catch { }

See here for more.

Answer 2

UIImage has no URL or file information. It's just a collection of bytes representing the pixel color data. If you get the UIImage from a UIImagePicker then you can get the URL to the original image in the asset library. But you must get this URL in the image picker delegate method and you must keep track of it separately from the UIImage object.

Edit - based on the OP's comment, this is not the information being requested.

Answer 3

What you are looking for is the UIImagePickerControllerReferenceURL parameter provided by the delegate callback in the info dictionary. What you need to do is:

NSURL* imageURL = [info objectForKey:UIImagePickerControllerReferenceURL];

And it would look something like this:

assets-library://asset/asset.JPG?id=SOME_GUUID&ext=JPG

You could use this latter to refer back to the same image you got in the UIImage* in the callback.

Answer 4

You could subclass UIImage and create an override initWithURL: to save the URL to a created property... something like this.

+ (id) initWithURL:(NSURL*)url
{
    [super initWithURL:url];
    self.url = url;
}